Stereo imaging quality evaluation in a full-color three-dimensional display system

To evaluate the light field display system with a liquid crystal display (LCD) and a holographic functional screen (HFS), the voxel theory based on the ray tracing is used. By analyzing the voxels defined by the cases of corresponding pixels overlapping completely and partially in the image space, the resolution characteristics of the system are discussed. The theoretical model is verified in the reconstruction experiment of a resolution target and compared with the calculation result of the presented system. Finally, we give an optimization method for the display image quality.     

双层芯色散补偿光子晶体光纤

为了抑制通信系统中脉冲的展宽,根据色散补偿理论,提出了一种由单一石英材料制成的双层芯光子晶体光纤(DCCPCF). 该光纤的色散值在155μm处可达到-6000ps/(nm〖DK〗•km). 理论分析表明,在传输过程中内芯基模和外芯缺陷模以相位匹配波长为临界状态,在内芯与外芯之间相互交替传输,并在匹配波长处因模式发生强烈耦合而引起折射率产生大幅度波动. 通过对结构参数d1、d2变化的情况下色散曲线的扰动情况进行分析,可为实际制备工作提供一定的理论指导.     

平坦色散高非线性光子晶体光纤的制备与实验

运用改进的全矢量有效折射率法(IFVEIM),课题组自行设计了一种在900 nm附近具有低平坦色散高非线性特性的光子晶体光纤.并且在改进工艺的基础上,采用中心抽真空挤压法对其进行了制备.虽然所制得光纤的结构参数与理论设计值存在一定的偏差,但其在所研究波段内色散值仅为0.5 ps/km/nm,非线性系数值则达到了35(W*km)-1,这在当前规则结构的纯硅光子晶体光纤中已经很高.最后,我们对其进行了非线性实验测试,其在400～1 400 nm的波段范围内展现出了宽平坦的超连续谱.     

Characteristics of gain and pump-to-signal RIN transfer in a dual-pump SOPA with Raman effect

We investigate the spectra of the gain and pump-to-signal relative intensity noise (RIN) transfer in silicon optical parametric amplifier (SOPA) with Raman effect, and draw a conclusion that Raman effect makes the spectra narrower from 260 nm to 180 nm. A maximum gain also appears at 1622 nm. Moreover, the effects of the related parameters in SOPA on the gain and the pump-to-signal RIN transfer characteristics are also discussed. The high gain (16 dB) and low pump-to-signal RIN transfer (7 dB) can be obtained by using the appropriate parameters of pump and silicon waveguide.     

A novel scheme for synchronous optical sampling based on multicast parametric process

We propose a novel scheme for synchronous optical sampling based on multicast parametric process. The linearly chirped and time-broadened pulses are utilized to replace the traditional mode-locked sampling pulses. An optical sampling rate of 80 Gbit/s is realized by using only one sampling source with repetition rate of 10 GHz.     

三种低损耗低平坦色散光子晶体光纤的设计

运用多极法理论,以内四层为研究对象,在三种情况下通过改变包层孔孔径d,设计了三种结构的光子晶体光纤.在包层中内四层空气孔孔径变化,而孔间距保持不变的情况下,数值模拟了其色散系数、限制损耗和基模有效折射率随波长变化的关系和光波模场的存在情况.模拟过程充分展示了所设计的光纤在1.2～1.8μm的宽波段范围内具有低损耗、低平坦色散的传输特性.     

Investigation on bismuth-oxide photonic crystal fiber for optical parametric amplification

A hexagonal solid-core bismuth-oxide micro-structure fiber is developed to balance its dispersion and nonlinearity.This simulation and calculation results show that the bismuth-oxide photonic crystal fiber(Bi-PCF) has near zero dispersion around 1550 nm.Its dispersion slop in the communication wavelength range is also relatively flat.Moreover,both nonlinear coefficient and model field distribution are obtained.Compared with the experimental results by SiO2-PCF,it can be seen that the Bi-PCF shows excellent characteristics for the optical parametric amplification(OPA).     

高线宽容忍度的高谱效SSB-PAM-DD方案

针对低成本下的高色散（CD）稳健性单边带（SSB）直接检测（DD）,对3种单边带脉冲幅度调制方案进行了分析,其中在发射端加入下变频的方案可获得最大频谱利用率,但恶化了系统对激光器线宽的容忍度。鉴于此,根据单边带脉冲幅度调制信号的特性,提出了一种包含相位损伤免疫均衡算法和改进盲相位补偿算法的数字信号处理方案。仿真结果表明,针对112 Gbit/s的单边带脉冲幅度直接检测,无论是背靠背还是传纤80 km场景,在同一误码率阈值下改进方案可容忍线宽为1 MHz,而原始方案仅为100 kHz,实现了高谱效、高线宽容忍度的低成本单边带脉冲幅度调制信号传输。     

光子晶体光纤中的反斯托克斯现象的研究

利用自制的光子晶体光纤(PCF),通过逐渐增加抽运脉冲的中心波长λ0,使其主要处于反常色散区,观测到了不同非线性效应作用下的频谱变化尤其是显著的反斯托克斯现象.通过调节耦合光束的入射方向,使光纤稳定输出为第一高阶模.在λ0达到并超过第一高阶模的零色散波长(820 nm)的过程中,抽运波工作在反常色散区,其向反斯托克斯波的能量转化逐渐增强.尤其当λ0超过860 nm之后,反斯托克斯波的强度可达到抽运波剩余强度的5倍,转换效率达到了80%.     

PCF中群速度失配和高阶色散对孤子自俘获的影响

基于分步傅里叶方法,仿真研究了光子晶体光纤(PCF)在反常色散区的群速度失配因子δ、高阶色散(主要是三阶色散)对孤子自俘获效应的影响.研究结果表明:随着群速度失配δ的增大,两偏振分量的平均振幅差值也增大,孤子自俘获效应变差;三阶色散量增大时,孤子自俘获效应变差.因此,只有选择合适的特性参数值才可以得到比较好的孤子自俘获效应,此特点可用于实现光开关等光信号处理功能器件.